Module, nozzle and method for dispensing controlled patterns of liquid material

ABSTRACT

A liquid dispensing module and nozzle or die tip for dispensing at least one liquid filament from a liquid discharge passage onto at least one moving strand. A strand guide is used for guiding each strand past the nozzle and/or locating each strand relative to the discharged liquid filament. The nozzle includes a process air outlet that supplies a stream of process air impinging each moving strand before the liquid filament is dispensed onto the strand.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. ProvisionalApplication No. 60/442,434, filed Jan. 24, 2003, the disclosure of whichis hereby incorporated by reference herein in its entirety.

FIELD OF THE INVENTION

[0002] The present invention generally relates to a liquid materialdispensing apparatus and nozzle and, more specifically, to an apparatusand nozzle for dispensing controlled patterns of liquid adhesive strandsor filaments.

BACKGROUND OF THE INVENTION

[0003] Many reasons exist for dispensing liquid adhesives, such as hotmelt adhesives, in the form of a thin filament or strand with acontrolled pattern. Conventional patterns used in the past have beenpatterns involving a swirling effect of the filament by impinging thefilament with a plurality of jets of air. This is generally known ascontrolled fiberization (CF) in the hot melt adhesive dispensingindustry. Controlled fiberization techniques are especially useful foraccurately covering a wider region of a substrate with adhesivedispensed as single filaments or as multiple side-by-side filaments fromnozzle passages having small diameters, such as on the order of 0.010inch to 0.060 inch. The width of the adhesive pattern placed on thesubstrate can be widened to many times the width of the adhesivefilament itself.

[0004] Controlled fiberization techniques are often used to providebetter control over adhesive placement. This is especially useful alongthe edges of a substrate and on very narrow substrates, for example,such as on strands of material (e.g., LYCRA®) used in the leg bands ofdiapers. Other adhesive filament dispensing techniques and apparatushave been used for producing an oscillating pattern of adhesive on asubstrate or, in other words, a stitching pattern in which the adhesivemoves back-and-forth generally in a zig-zag form on the substrate.Typically, these dispensers or applicators have a series of liquid andair orifices arranged on the same plane. Conventional swirl nozzles ordie tips typically have a central adhesive discharge passage surroundedby a plurality of air passages. The adhesive discharge passage iscentrally located on a protrusion that is symmetrical in a full circleor radially about the adhesive discharge passage. A common configurationfor the protrusion is conical or frustoconical with the adhesivedischarge passage exiting at the apex. The air passages are typicallydisposed at the base of the protrusion. The air passages are arranged ina radially symmetric pattern about the central adhesive dischargepassage, as in the protrusion itself. The air passages are directed in agenerally tangential manner relative to the adhesive discharge passageand are all angled in a clockwise or counterclockwise direction aroundthe central adhesive discharge passage.

[0005] Conventional meltblown adhesive dispensing apparatus typicallycomprise a die tip having multiple adhesive or liquid discharge passagesdisposed along an apex of a wedge-shaped member and air passages of anyshape disposed along the base of the wedge-shaped member. Thewedge-shaped member is not a radially symmetric element. Rather, it istypically elongated in length relative to width. The air is directedfrom the air discharge passages generally along the side surfaces of thewedge-shaped member toward the apex, and the air impacts the adhesive orother liquid material as it discharges from the liquid dischargepassages to draw down and attenuate the filaments. The filaments aredischarged in a generally random manner.

[0006] Various types of nozzles or die tips, such as those of the typedescribed above, have been used to dispense adhesive filaments onto oneor more elastic strands. Each strand is typically aligned and directedby a guide proximate the corresponding adhesive discharge passage. Thestrands tend to acquire airborne particulates present in the environmentsurrounding the liquid adhesive dispensing apparatus. These airborneparticulates consist of dust and other contaminants that primarilyoriginate from the processing operations performed by the productionline. In addition, the strands may be intentionally coated withparticulates, such as talc, to facilitate movement through the guide.

[0007] As each strand interacts with the corresponding guide, theparticulates, regardless of origin, may be wiped off and accumulate oragglomerate into larger masses. The agglomerated masses of particulatesmay dislodge from the guide and incorporate into the dispensed adhesivefilament. For example, the agglomerated mass may be dislodged by a knotis formed between the trailing end of a first length of strand materialand the leading edge of a second length of strand material joined toprovide a continuous strand. Alternatively, the agglomerated mass mayremain resident in the guide and increase in dimensions to such anextent that the strand itself is displaced or removed from the guide. Inmulti-strand dispensing operations, an adjacent guide may capture thedisplaced strand, which disrupts the application of adhesive to thestrands and ultimately produces defective product because the strandsare adhesively bonded to a substrate with improper positioning. Thereduction in product quality may be significant and may increase themanufacturing cost.

[0008] Another difficulty associated with dispensing adhesive onto aguided, moving strand occurs during periods in which the production lineis idled, such as for line maintenance. The strand or strands may befixed in position and in contact with heated surfaces of the adhesivenozzle or die tip. Heat transferred from the nozzle or die tip to eachstrand may result in strand breakage because of temperature effects. Asa result, the downtime of the production line may be increased forreconnection of the strand break or substitution of an unbroken strand.

[0009] Yet another difficulty associated with dispensing adhesive onto aguided, moving strand arises from contact between the strand and theadhesive nozzle or die tip. Specifically, the strand wears the metalsurfaces of the nozzle or die tip and the metal surfaces of the guide orguides due to frictional wear. Eventually, the wear may necessitatereplacement of the nozzle, die tip or guide. Moreover, the contactbetween the strand and these metal surfaces causes drag on the strand,which may reduce the predictability of adhesive application or mayresult in broken strands.

[0010] What is needed, therefore, is a liquid dispensing module fordispensing a liquid filament onto a substrate in which the difficultiesassociated with strand guiding are reduced or eliminated.

SUMMARY OF THE INVENTION

[0011] The invention is directed to an adhesive applicator and a nozzlefor an adhesive applicator in which particulates residing on a strandare removed so that those particulates are less likely to accumulate onsurfaces associated with the nozzle. Such surfaces include, but are notlimited to, the guide or guides steering a moving strand for accurateplacement of an adhesive filament dispensed from a liquid dischargeoutlet in the nozzle. Moreover, an adhesive applicator and nozzleaccording to the principles of the invention may reduce or eliminate thecontact between the strand and the guide or guides steering the strand.As a result, the aforementioned difficulties associated with strandguiding are reduced or eliminated.

[0012] A nozzle of the invention includes a nozzle body having a liquidsupply port, a liquid discharge passage connected in fluid communicationwith the liquid supply port, and a process air supply port. The nozzleincorporates a mounting surface configured for mounting the nozzle bodyto a valve module. The nozzle further includes a process air outletformed in the nozzle body, which is coupled in fluid communication withthe process air supply port. The process air outlet is oriented todischarge an air stream impinging the strand before the liquid filamentis dispensed from the liquid discharge passage onto the strand.

[0013] In accordance with the principles of the invention, a method isprovided for dispensing a liquid filament onto a strand from a liquiddispensing nozzle having a liquid discharge passage. The methodcomprises moving the strand relative to the nozzle and dispensing theliquid filament from the liquid discharge passage onto the strand. Thestrand is impinged with process air upstream of the liquid dischargepassage before the liquid filament is dispensed onto the strand.

[0014] The principles of the invention are applicable to dispensingmodules and adhesive applicators having one or more sets of liquiddischarge passages. Each set of liquid discharge passages dispenses aliquid filament that is applied to one or more multiple moving strands.The strands are subsequently applied in a pattern to a substrate.Therefore, it is desirable to provide a nozzle having multiple guideseach of which is associated with a liquid discharge passage and each ofwhich steers one of the multiple moving strands to promote accurateplacement of the liquid filament. For each strand, the principles of theinvention may be applied for removing particulates from the strand.

[0015] These and other features, objects and advantages of the inventionwill become more readily apparent to those of ordinary skill in the artupon review of the following detailed description, taken in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

[0016]FIG. 1 is a perspective view of a dispensing module including onenozzle or die tip constructed in accordance with a preferred embodimentof the invention;

[0017]FIG. 2 is an enlarged perspective view of the nozzle or die tip ofFIG. 1;

[0018]FIG. 3 is a front elevational view showing the discharge portionof the nozzle or die tip;

[0019]FIG. 4 is a side elevational view of the nozzle or die tip;

[0020]FIG. 4A is a cross-sectional view of the nozzle or die tip takenalong line 4A-4A of FIG. 3;

[0021]FIG. 5 is an enlarged view of the nozzle discharge portion shownin FIG. 3;

[0022]FIG. 6 is a rear elevational view of the nozzle or die tip;

[0023]FIG. 7 is a top view of the nozzle or die tip;

[0024]FIG. 8 is a front elevation view of an alternative nozzle or dietip in accordance with the invention;

[0025]FIG. 9 is a perspective view of another exemplary dispensingmodule and nozzle of the present invention;

[0026]FIG. 10 is a perspective view of the nozzle of FIG. 9;

[0027]FIG. 11 is a side view of the nozzle of FIG. 10, depicting air andliquid passages of the nozzle;

[0028]FIG. 12 is a cross-sectional view of the nozzle of FIG. 10,through the center of the nozzle;

[0029]FIG. 13 is a view of the nozzle of FIG. 10, taken along lines13-13 in FIG. 12;

[0030]FIG. 14 is a detail view of the air and discharge outlets of FIG.13;

[0031]FIG. 15 is a cross-sectional view of an alternative embodiment ofa nozzle in accordance with the principles of the invention;

[0032]FIG. 16 is a bottom view of the nozzle of FIG. 15 taken generallyalong line 16-16 of FIG. 15, shown with the liquid filament absent forclarity; and

[0033]FIG. 17 is a cross-sectional view of an alternative embodiment ofa nozzle in accordance with the principles of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0034] For purposes of this description, words of direction such as“upward”, “vertical”, “horizontal”, “right”, “left” and the like areapplied in conjunction with the drawings for purposes of clarity andproviding a reference frame in the present description only. As is wellknown, liquid dispensing devices may be oriented in substantially anyorientation, so these directional words should not be used to imply anyparticular absolute directions for an apparatus consistent with theinvention.

[0035] Referring first to FIGS. 1 and 2, an exemplary dispensing module10 of the present invention is shown. Dispensing module 10 generallycomprises a module body 12 including a central body portion 14 and alower body portion 18. An upper cap (not shown) is secured to centralbody portion 14 by fasteners (not shown). Central body portion 14includes fasteners 22 for securing module 10 to a suitable support, suchas a manifold (not shown) which supplies liquid, such as hot meltadhesive, to module 10. Lower body portion 18 is secured to central bodyportion 14 by respective pairs of fasteners 24, 26. A nozzle assembly ordie tip assembly 28 receives liquid and pressurized air from respectivesupply passages. Nozzle assembly 28 is secured to lower body portion 18and includes a nozzle or die tip 30. Fasteners 33 secure nozzle 30 tolower body portion 18. Module or applicator 10 is preferably of theon/off type and includes internal valve structure for selectivelydispensing liquid, such as hot melt adhesive or other viscous liquidtypically formed from polymeric material, in the form of one or morefilaments. A suitable module structure usable in connection with nozzle30 is part no. 309637 available from Nordson Corporation, Westlake,Ohio, which is the assignee of the present invention.

[0036] Referring first to FIGS. 2-8, a nozzle 30 is shown constructed inaccordance with the preferred embodiment. Nozzle 30 includes a body 32preferably formed from a metal such as brass and having a front surface34, a rear surface 36, an upper surface 38 and a lower surface 40. AV-shaped notch 42 is formed in lower surface 40 and is generally definedby a pair of converging opposite sidewalls 42 a, 42 b. Notch 42 servesas a guide to direct an infed strand 44 of substrate material past airand liquid outlets of nozzle body 32. Rear surface 36 is adapted to besecured against the face of a dispenser and receives liquid material,such as hot melt adhesive, through a liquid inlet port 46 extending intobody 32. Liquid inlet port 46 further communicates with a liquiddischarge passage 48 having a longitudinal axis 48 a extending in aplane which includes a centerline 43 of notch 42. In the exemplaryembodiment shown, axis 48 a forms an angle of 37° to lower surface 40.The liquid discharge passage 48 thus forms an acute angle with rearsurface 36. In another exemplary embodiment, the angle between theliquid discharge passage and the rear surface 36 is approximately 60° to80°. An outlet 48 b of liquid discharge passage 48 is located in asemi-circular recess 54 formed into front surface 34 proximate the apexof notch 42. The liquid discharge outlet 48 b is at the apex of afrustoconical protrusion 56 that extends from semi-circular recess 54 ina direction along axis 48 a. Air inlet recesses 50, 52 are formed intorear surface 36 and communicate with four air discharge passages 60, 62,64, 66 extending along respective axes 60 a, 62 a, 64 a, 66 a.

[0037] Air discharge passages 60, 62, 64, 66 exit at outlets 60 b, 62 b,64 b, 66 b on front surface 34 and on semi-circular recess 54, adjacentliquid discharge outlet 48 b best shown in FIGS. 3 and 4. Air dischargepassages 60, 62, 64, 66 discharge pressurized air generally toward axis48 a of liquid discharge passage 48, with compound angles bestcomprehended by reviewing both FIGS. 3-5. Holes 68, 70 extend throughbody 32 for receiving fasteners 33 (FIG. 1) used to secure nozzle 30 toa dispenser.

[0038] As viewed from the front surface 34 of nozzle body 32 (FIG. 3),axes 60 a, 64 a of air discharge passages 60, 64 are disposed atapproximately 10° and 85°, respectively, from the axis 48 a of liquiddischarge passage 48.

[0039] Axes 62 a, 66 a of passages 62, 66 are disposed at approximately65° and 40° from axis 48 a, as measured from lower surface 40. As viewedfrom the side of nozzle body 32, the axes 60 a, 62 a, 64 a, 66 a of airdischarge passages 60, 62, 64, 66 form angles of approximately 18°, 29°,37°, and 51° with axis 48 a of liquid discharge passage 48 as bestdepicted in FIG. 4.

[0040] The four discharge outlets 60 b, 62 b, 64 b, 66 b have centerswhich are positioned along a common radius from a point corresponding tothe location of a substrate received into notch 42. In an exemplaryembodiment, the centers of air discharge outlets 60 b, 62 b, 64 b, and66 b are positioned along a radius located from a point which is0.027-inch from the apex of notch 42 when notch 42 has converging sidewalls 42 a and 42 b separated by an angle of 60°. This corresponds to astrand 44 having a cross sectional diameter of 0.031 inch.

[0041] The four discharge outlets 60 b, 62 b, 64 b, 66 b are arranged toform a generally square pattern below the liquid discharge outlet 48 bwhen viewed along axis 48 a, as depicted in FIG. 5. Pressurized air fromair discharge outlets 60 b, 62 b, 64 b, 66 b is directed in directionsgenerally tangential to the liquid filament discharging from passage 48,as opposed to directly impacting the filament discharging from passage48. The size of the swirl pattern produced by pressurized air from airdischarge outlets 60 b, 62 b, 64 b, 66 b impinging upon liquid filamentas it exits liquid discharge outlet 48 b may be adjusted by varying theangular orientation of air discharge passages 60, 62, 64, 66.

[0042]FIGS. 1 and 2 illustrate operation of an exemplary nozzle of thepresent invention and a swirl pattern which is produced by the exemplarynozzle. A substrate in the form of a strand 44 is received into notch 42and moves in a direction indicated by the arrow 72. As the strand 44passes beneath liquid discharge outlet 48 b, a liquid filament 74 isdispensed from the outlet 48 b generally also in the direction of arrow72, but with a downward angle as well, and deposited on the strand 44.Jets of pressurized air from air discharge outlets 60 b, 62 b, 64 b, and66 b are directed generally tangentially toward the liquid filament 74,as depicted by arrows 76, 78, 80, 82 in FIG. 2. The jets of pressurizedair cause the liquid filament 74 to move in a swirling motion as it isdeposited on the strand 44. After the filament 74 has been deposited onthe strand 44, portions of the liquid filament 74 may be drawn bygravity and/or centrifugal forces to wrap around the substrate 44. Thesize of the swirl patterns may be varied by varying the number andarrangement of the air jets (i.e., discharge outlets).

[0043]FIG. 8 illustrates one of many possible alternative configurationsfor a nozzle or die tip 30′. In this regard, the front face of nozzle30′ is a flat surface and is not beveled or inset to angle the variouspassages downwardly as in the first embodiment. All other referencenumbers are identical as between FIGS. 1-7 and FIG. 8 and thedescription thereof may be referred to above for an understanding ofthis embodiment as well.

[0044] Referring to FIGS. 9-14, there is shown another exemplarydispensing module 90 and nozzle 98 according to the present invention.The dispensing module 90 depicted in FIG. 9 is similar to the exemplarydispensing module 10 of FIG. 1, having a central body portion 92 and alower body portion 94, but further including a quick disconnectmechanism 96 for facilitating the installation and removal of variousnozzles or dies from the dispensing module 90, as more fully describedin U.S. patent application Ser. No. 09/814,614, filed on Mar. 22, 2001and assigned to the assignee of the present invention. FIG. 9 furtherillustrates another exemplary nozzle 98 coupled to the dispensing module90 and secured with the quick disconnect mechanism 96. Nozzle 98receives liquid and pressurized air from the dispensing module 90 anddispenses a filament of liquid material 100 in a controlled pattern to astrand of substrate material 102 moving relative to the die 98,generally in the direction of arrow 104, in a manner similar to thatdescribed above with respect to nozzle 30.

[0045] Referring now to FIG. 10, the exemplary nozzle 98 is shown inmore detail. Nozzle 98 comprises a nozzle body 106 and includesprotrusions 110, 112 and angled cam surfaces 114, 116, as more fullydescribed in U.S. patent application Ser. No. 09/814,614, to facilitatecoupling the nozzle 98 with the dispensing module 90. The nozzle body106 includes a first side 118 configured to mount to the lower portion94 of the dispensing module 90. The first side 118 includes a liquidsupply port 120 and first and second process air supply ports 122, 124which mate to corresponding liquid and air supply passages in thedispensing module 90 in a manner similar to that described above formodule 10. As depicted in FIGS. 10-12, the exemplary nozzle body 106 hasa generally wedge-shaped cross-section including second and third (i.e.,downstream and upstream) sides 126, 128. A frustoconically-shapedprotrusion 130 extends from the second side 126 of the nozzle body 106and includes a liquid discharge outlet 132 disposed on a distal end ofthe protrusion 130.

[0046] The liquid discharge outlet 132 is in fluid communication with aliquid discharge passage 134, which in turn is in communication with theliquid supply port 120 by way of a liquid passage 135, whereby liquidmaterial from the module 90 may be dispensed from the liquid dischargeoutlet 132 to the strand 102 of substrate material as more clearlydepicted in FIGS. 11 and 12. At least a portion of the liquid dischargepassage 134 is oriented to form an acute angle with a plane parallel tothe first side 118, and thus forms an angle with a directioncorresponding to of movement of the strand 102, generally indicated byarrow 104. The liquid discharge passage of the exemplary embodiment isinclined at approximately 20° to the first side, whereby the liquidmaterial is dispensed from the liquid discharge outlet to the strand andgenerally in the direction of strand movement.

[0047] The second side 126 of the nozzle body 106 further includes aplurality of air discharge outlets 136 proximate the liquid dischargeoutlet 132 and in fluid communication with air discharge passages 138,140 by way of respective air passages 139,141 which extend to the airsupply ports 122, 124 on the first side 118 of the nozzle body 106. Theair discharge passages 138, 140 of the exemplary nozzle body 106 areinclined at approximately 20° and approximately 28° from an axis throughliquid passage 135. As shown in FIGS. 13 and 14, the air dischargeoutlets 136 are arranged generally around the base of the frustoconicalprotrusion 130 and are configured to direct process air toward theliquid filament 100 dispensed from the liquid discharge outlet 132 in amanner similar to that described above for nozzle 30.

[0048] In the exemplary nozzle body 106, four air discharge outlets 136are disposed in a generally square pattern around the liquid dischargeoutlet 132 at the base of the frustoconical protrusion 130. Diagonallyopposite air discharge passages 138, 140 or, in other words, airdischarge passages disposed at opposite corners of the square-shapedpattern, are symmetric and disposed in planes that are at least nearlyparallel to each other. The air discharge passages 138, 140 are eachoffset from axes 152 that are normal to a longitudinal axis of theliquid discharge passage 134, and each forms a true angle ofapproximately 30° with the longitudinal axis of the liquid dischargepassage 134 such that the air stream discharged from each air dischargepassage 138 is tangential to the liquid filament 100 discharged from theliquid discharge passage 134, as opposed to directly impacting thefilament 100. This arrangement of air and liquid discharge passagesprovides a liquid filament which is moved in a controlled manner as itis dispensed from the liquid discharge passage to create a desiredpattern on the strand 102 of substrate material. Variation of thepattern is possible by adjusting the offset spacing and orientation ofthe air discharge passages 138, 140 relative to the liquid dischargepassage 134, as will be apparent to those skilled in the art.

[0049] The nozzle body 106 further includes a notch 150 formed into anend of the nozzle body 106 opposite the first side 118 and proximate theliquid discharge outlet 132 to direct the strand 102 of substratematerial past the air and liquid discharge outlets 132, 136 disposed onthe second side 126 of the nozzle body 106. As shown more clearly inFIGS. 11 and 12, the notch 150 extends between an upstream entrance onthe third side 128 and a downstream exit on the second side 126 of thenozzle body 106. In an exemplary embodiment, the second and third sides126, 128 are configured to form acute angles with the first side 118. Inone exemplary embodiment, the second side 126 forms an angle ofapproximately 60-80° with the first side 118. In another aspect of theinvention, the third side 128 forms an angle no greater thanapproximately 70° with the first side 118. Advantageously, the angle ofthe third side 128 facilitates the passage of knots formed in the strand102 without causing breakage of the strand 102. These knots aretypically formed in the infed strand material, for example, when thetrailing end of a first length of strand material is secured to theleading end of a second length of strand material from a supply topermit continuous operation of the module 90.

[0050] With reference to FIGS. 15 and 16 in which like referencenumerals refer to like features in FIGS. 9-14, a nozzle 160 is depictedthat is capable of being coupled with a dispensing module, such asdispensing module 90 (FIG. 9). Nozzle 160 receives liquid andpressurized air from the dispensing module 90, when coupled thereto andduring operation, and dispenses a filament of liquid material 100 in acontrolled pattern to a strand 102 of substrate material moving relativeto the nozzle 160, generally in the direction of arrow 104, in a mannersimilar to that described above with respect to nozzles 30 and 98.

[0051] Nozzle 160 includes a supply passageway 162 coupled in fluidcommunication with the second process air supply port 124, whichreceives process air from an air supply passage of the dispensing module90. It is contemplated by the invention that the supply passageway 162may be coupled in fluid communication with the first process air supplyport 122 or with another air supply port (not shown) for supplyingprocess air to the supply passageway 162. Coupled in fluid communicationwith the supply passageway 162 is a discharge passageway 164 thatincludes a process air outlet 166 exiting a base or planar surface 168of notch 150. The air flow discharged from the outlet 166, indicatedgenerally by arrow 169, is directed generally parallel to a longitudinalaxis 170 of the discharge passageway 164. The longitudinal axis 170 isinclined relative to the planar surface 168, and relative to the strand102, and is oriented generally toward the third side 128 of nozzle 160.Typically, the longitudinal axis 170 is inclined in an upstreamdirection at an acute angle, α, of between about 1° and about 89°,typically between about 60° and about 80°, and most typically at about75° relative to a line 169 aligned parallel to the length of strand 102.As a result, the air flow, or at least a significant component of theair flow, is angled in an upstream direction opposite to the movementdirection 104 of strand 102. In contrast, the process air dischargedfrom air discharge outlets 136 is directed downstream generally in thedirection of motion 104 and proximate to the liquid discharge outlet132.

[0052] The air flow from outlet 166 impinges the strand 102 proximate toan upstream entrance to the notch 150 and, hence, does not influence thecontrolled movement of liquid filament 100 dispensed from the liquiddischarge outlet 132 that creates a desired pattern on strand 102.Process air from air discharge outlets 136 impinges the liquid filament100 but, because the air discharge outlets 136 are positioned on thesecond side 126 of the nozzle 160, the air streams from outlets 136 donot operate for particulate removal. Conversely, the air stream fromoutlet 166 does not impinge the liquid filament 100 and, therefore, doesnot participate in creating the desired pattern on the strand 102. Inother words, the air stream from outlet 166 and the air streams fromoutlets 136 operate independently of one another.

[0053] Notch 150 includes opposing, spaced-apart sidewalls 150 a and 150b projecting from planar surface 168 that operate as an invertedU-shaped guide having for positioning the strand 102 relative to theliquid discharge outlet 132. The sidewalls 150 a, 150 b limit thelateral or transverse range of movement of the strand 102 relative tothe liquid discharge outlet 132 so that strand 102 is generally alignedwith outlet 132. The planar surface 168 limits the movement of thestrand 102 in one vertical direction as strand 102 moves through notch150, if the strand 102 contacts surface 168.

[0054] Particulates 172 are associated with strand 102 before itsarrival at nozzle 160 either intentionally or as a contaminant from thesurrounding environment. The air flow discharged from outlet 166 has avelocity or magnitude sufficient for overcoming the forces adhering theparticulates 172 to the strand 102 and removing particulates 172 fromstrand 102 either before, as, or after each particulate 172 carried bystrand 102 enters notch 150. The orientation of the longitudinal axis170 and the air flow relative to the planar surface 168 and the strand102 determines the specific position relative to notch 150 at which eachparticulate 172 is removed from strand 102. The magnitude of the airflow is determined by the dimensions of supply passageway 162, dischargepassageway 164, and the outlet 166, and also by the pressure of theprocess air in second process air supply port 124. The generallyupstream direction of the air flow discharged from outlet 166 propelsthe particulates 172 removed from strand 102 away from the notch 150 andthe strand 102.

[0055] The air flow from outlet 166 reduces or eliminates the trappingand accumulation of particulates 172 in notch 150, which reduces orprohibits the presence of agglomerated masses of particulates 172 withinnotch 150. Because agglomerated masses of particulates 172 are lesslikely to be formed, their incorporation into the dispensed adhesivefilament 100 is less likely. Moreover, strands 102 undergoingmulti-strand dispensing are less likely to be displaced from theircorresponding notches 150 by strand knots and the like due to theabsence of agglomerated particulates 172. Consequently, the product withwhich the strands 102 are incorporated is less likely to be defectivedue to improper strand positioning.

[0056] The air flow from outlet 166 also reduces the incidence of strandbreakage if strand 102 is stationary within notch 150, such as whenproduction line maintenance is performed. The strand 102 is proximate toor in contact with planar surface 168 and sidewalls 150 a and 150 bforming the notch 150 (i.e., the strand guide). The air flow from outlet166 may cool the strand 102 and/or may operate to space the strand 102from the strand guide so that the strand 102 and strand guide arenon-contacting so as to reduce heat transfer from the nozzle 160 tostrand 102. For purposes of cooling, the temperature of the process airemitted from outlet 166 may be lower than the temperature of thesidewalls 150 a and 150 b and planar surface 168 defining notch 150. Theair flow from outlet 166 may also space the strand 102 from planarsurface 168 of the strand guide as the strand 102 is moving in movementdirection 104. This separation reduces the contact between strand 102and planar surface 168 so that wear on surface 168 is reduced and,moreover, reduces the frictional drag acting on strand 102.

[0057] With reference to FIG. 17 in which like reference numerals referto like features in FIGS. 15 and 16, a nozzle 180 is configured to becoupled with a dispensing module, such as dispensing module 90 (FIG. 9).Nozzle 180 receives liquid and pressurized air from dispensing module90, when coupled thereto and during operation, and dispenses a filamentof liquid material 100 in a controlled pattern to a strand 102 ofsubstrate material moving relative to the nozzle 180, generally in thedirection of arrow 104, in a manner similar to that described above withrespect to nozzles 30, 98 and 160.

[0058] Nozzle 180 includes a supply passageway 182 coupled in fluidcommunication with second process air supply port 124, which receivesprocess air from an air supply passage of the dispensing module 90. Itis contemplated by the invention that the supply passageway 182 may becoupled in fluid communication with the first process air supply port122 or with any other air supply port (not shown) for supplying processair to the supply passageway 182. A discharge passageway 184 is coupledin fluid communication with the supply passageway 182 and includes anoutlet 186 exiting third side 128. Process air is discharged from theoutlet 186 generally in a direction of arrow 187, which is directedgenerally parallel to a longitudinal axis 190 of the dischargepassageway 184. Longitudinal axis 190 is inclined relative to the strand102. Typically, the longitudinal axis 190 is inclined at an angle, β, ofbetween about 20° and about 90°, typically between about 35° and about55°, and most typically about 45°. As a result, the air flow, or atleast a significant component of the air flow, is angled in an upstreamdirection opposite to the movement direction 104 of strand 102. The airflow impinges the strand 102 proximate to an upstream entrance to thenotch 150. The air flow from outlet 186 does not influence thecontrolled movement of liquid filament 100 dispensed from the liquiddischarge outlet 132 that creates a desired pattern on strand 102.

[0059] The air flow discharged from outlet 186 has a velocity ormagnitude sufficient for overcoming the forces adhering the particulates172 to the strand 102 and removing particulates 172 from strand 102before each particulate 172 carried by strand 102 enters notch 150. Themagnitude of the air flow is determined by the dimensions of supplypassageway 182, discharge passageway 184, and the outlet 186, and alsoby the pressure of the process air in second process air supply port124. The generally upstream direction of the air flow discharged fromoutlet 186 propels the particulates 172 removed from strand 102 in adirection, generally indicated by arrow 194, away from the notch 150 andthe strand 102. As a result, particulates 172 are less likely to becometrapped and accumulate into an agglomerated mass within notch 150, whichprovides the benefits described above.

[0060] The principles of the invention have been illustrated for guidesstructured as notch 150. However, the cleaning of particulates 172 fromthe strand 102 are applicable to other types of guides (not shown), suchas undriven rollers, upstream from the dispensing module 90. In theseinstances, the air flow discharged from the outlet 166 or the outlet 186impinges either the roller of the strand 102 upstream from the roller.If the rollers are coated with liquid, the particulates 172 couldcollect and accumulate, as mediated by the presence of the liquid, ifnot otherwise removed by the air streams.

[0061] While the present invention has been illustrated by a descriptionof various preferred embodiments and while these embodiments have beendescribed in some detail, it is not the intention of the applicants torestrict or in any way limit the scope of the appended claims to suchdetail. Additional advantages and modifications will readily appear tothose skilled in the art. The various features of the invention may beused alone or in numerous combinations depending on the needs andpreferences of the user. This has been a description of the presentinvention, along with the preferred methods of practicing the presentinvention as currently known. However, the invention itself should onlybe defined by the appended claims.

What is claimed is:
 1. A nozzle for dispensing a liquid filament onto astrand, comprising: a nozzle body having a liquid supply port, a processair supply port, and a liquid discharge passage connected in fluidcommunication with said liquid supply port; a mounting surfaceconfigured for mounting said nozzle body to a valve module; and aprocess air outlet formed in said nozzle body, said process air outletcoupled in fluid communication with said process air supply port, andsaid process air outlet oriented to discharge an air stream impingingthe strand before the liquid filament is dispensed from said liquiddischarge passage onto the strand.
 2. The nozzle of claim 1 furthercomprising: a strand guide coupled directly with said nozzle body andhaving opposed first and second sidewalls positioned adjacent saidliquid discharge passage, said first and second sidewalls constraininglateral movement of the strand relative to said liquid dischargepassage.
 3. The nozzle of claim 2 wherein said process air outlet ispositioned between said opposed first and second sidewalls of saidstrand guide.
 4. The nozzle of claim 2 wherein said nozzle body includesa downstream surface and an upstream surface opposite to said downstreamsurface, said liquid discharge outlet being located on said downstreamsurface and said process air outlet being located on said upstreamsurface.
 5. The nozzle of claim 2 wherein said process air stream fromsaid air outlet is oriented to maintain a non-contacting relationshipbetween said strand guide and the stand.
 6. The nozzle of claim 1wherein said nozzle body includes substantially an upstream surface anda downstream surface opposite to said upstream surface, said process airoutlet being formed in said upstream surface and said liquid dischargepassage being formed in said downstream surface.
 7. The nozzle of claim6 where said nozzle body further includes a plurality of air dischargepassages connected in fluid communication with said process air supplyport, said plurality of air discharge passages formed on said downstreamsurface and angled in a direction generally toward said liquid dischargepassage.
 8. An applicator for dispensing a liquid filament onto a movingsubstrate, comprising: a module body having a liquid supply passage andan air supply passage; a nozzle body having a liquid discharge passageconnected in fluid communication with said liquid passage; and a processair outlet formed in said nozzle body, said process air outlet coupledin fluid communication with said process air supply port, said processair outlet oriented to discharge an air stream impinging the strandbefore the liquid filament is dispensed from said liquid dischargepassage onto the strand.
 9. The applicator of claim 8 furthercomprising: a strand guide coupled directly with said nozzle body andhaving opposed first and second sidewalls positioned adjacent saidliquid discharge passage, said first and second sidewalls constraininglateral movement of the strand relative to said liquid dischargepassage.
 10. The applicator of claim 9 wherein said process air outletis positioned between said opposed first and second sidewalls of saidstrand guide.
 11. The applicator of claim 9 wherein said nozzle bodyincludes a downstream surface and an upstream surface opposite to saiddownstream surface, said liquid discharge outlet being located on saiddownstream surface and said process air outlet being located on saidupstream surface.
 12. The applicator of claim 9 wherein said process airstream from said air outlet is oriented to maintain a non-contactingrelationship between said strand guide and the stand.
 13. The applicatorof claim 8 wherein said nozzle body includes an upstream surface and adownstream surface opposite to said upstream surface, said process airoutlet being formed in said upstream surface and said liquid dischargepassage being formed in said downstream surface.
 14. The applicator ofclaim 13 where said nozzle body further includes a plurality of airdischarge passages connected in fluid communication with said processair supply port, said plurality of air discharge passages formed on saiddownstream surface and angled in a direction generally toward saidliquid discharge passage.
 15. A method of dispensing a liquid filamentonto a strand from a nozzle having a liquid discharge passage, themethod comprising: moving the strand relative to the nozzle; impingingthe strand with process air upstream of the liquid discharge passagebefore the liquid filament is dispensed onto the strand; and dispensingthe liquid filament from the liquid discharge passage onto the strand.16. The method of claim 15 further comprising: guiding the strandrelative to the liquid discharge passage with a strand guide.
 17. Themethod of claim 16 wherein the nozzle includes the strand guide and anair discharge passage is located within the strand guide, and impingingthe strand with process air further comprises: discharging process airfrom the air discharge passage positioned within the strand guide in adirection that impinges the strand.
 18. The method of claim 16 whereinthe air directed toward the strand has a lower temperature than thestrand guide, and impinging the stand with process air furthercomprises: cooling the strand guide and the strand.
 19. The method ofclaim 16 wherein impinging the stand with process air further comprises:maintaining the strand in a spaced relationship with the strand guide.20. The method of claim 15 wherein impinging the stand with process airfurther comprises: removing particulates from the strand.
 21. The methodof claim 15 further comprising: moving the liquid filament with jets ofpressurized air directed generally tangentially toward the liquidfilament.